Tell me that Europeans could quickly resolve any divisive, controversial issue as explosive (no pun intended) as gun ownership and regulation is in the US.

They don't need to. Despite being "culturally diverse, multi-racial, multi-language" and having spent much of the last 220 years fighting one another in various combinations at various times most of them disarmed their civilians decades ago. They don't need militias other than government controlled ones. France and Germany sorted out a far bigger problem between themselves after WW2. You folks don't seem to have got over your civil war yet.